Temperature dependence of the electron-spin resonance in nitrogen-rich amorphous silicon nitride

The intensity of the dark electron-spin-resonance (ESR) signal, which is commonly observed in nitrogen-rich hydrogenated amorphous silicon nitride (a-SiN1.6), is shown to depend on temperature. This temperature dependence is compared to that observed in amorphous arsenic (a-As), which has a similar thermally generated ESR signal, and to the temperature-independent ESR signal observed in a-Si. Comparisons of optically induced absorption spectra for a-SiN1.6 and a-As suggest that the defects contributing to the subband-gap absorption may not exhibit the strong electron-lattice interactions that characterize those in a-As but, rather, result most probably from large potential fluctuations. © 1994 The American Physical Society.